S80 NOSEGEAR FAILS TO RETRACT AFTER TKOF. MISCOM IN THE COCKPIT RESULTS IN CONFUSION AS TO ACFT CONFIGN AND AN ALTDEV ALT EXCURSION OCCURS.

Narrative

WHEN GEAR WAS RETRACTED ON TKOF; THE RED NOSEGEAR LIGHT REMAINED ILLUMINATED WITH ACCOMPANYING INCREASED WIND NOISE. THE APPROPRIATE CHKLIST WAS ACCOMPLISHED; BUT DID NOT RESOLVE THE PROB. I ELECTED TO RETURN TO LAX AND DID SO WITHOUT FURTHER INCIDENT. THE LNDG WAS MADE WITH A SOFT TOUCHDOWN. THE INITIAL PROB OCCURRED AT AN EXTREMELY BUSY TIME; IE; REVISED INITIAL ALT -- FREQ CHANGE; XING A FIX THAT REQUIRES A TURN; NORMAL CLEANUP; ETC; AND NOW AN ABNORMAL WITH A LOT OF ADDITIONAL NOISE. DURING ALL OF THIS; I HAD DECIDED TO LEAVE THE SLATS EXTENDED IN ORDER TO KEEP THE SPD DOWN. IN COMMUNICATING MY INTENT; EITHER I WASN'T CLR OR THE FO MISUNDERSTOOD AND THE SLATS WERE IN FACT RETRACTED. NOT REALIZING THIS; WHEN I ATTEMPTED TO LEVEL OFF; THE ACFT WAS NOT RESPONDING AT ALL AS I WAS ANTICIPATING. THIS RESULTED IN SOME MINOR ALTDEVS. PROBABLY NOT ENOUGH TO RING THE BELL WITH ATC; BUT TO GET AN ALERT IN THE COCKPIT. SUPPLEMENTAL INFO FROM ACN 356677: ATC FREQ: 134.35. ATC FACILITY: SOCAL DEP. LOCATION: 8 NM W OF LAX. WHILE CLEANING UP THE AIRPLANE AND PREPARING TO READ THE CHKLIST; I UNDERSTOOD THE CAPT TO ASK FOR SLATS RETRACT AND DID SO. ABOUT 20 SECONDS LATER; WHILE LEVEL AT 3000 FT; OUR ALT DEVIATED ABOUT 300 FT BELOW OUR ASSIGNED ALT.